There used to be a free App for this a decade ago. I don't even remember what it was called.
If you can't find a modern version, it's not all that hard to manually find the gaps between tracks using Audacity, and cut/paste into a new window. You can spend the winter with Audacity, manually removing the 10msec pops and clicks from old record->mixtape masterpieces.
Be prepared to splice with cellophane tape. Old cassettes can get brittle or sticky. Bring alcohol and swabs, to clean off your tape heads frequently. You'll probably have to do some re-equalization of the tracks use Audacity as well. The high frequencies, never great on tape anyway, become subdued after repeated plays. Audacity's "Plot Spectrum" capacity offers a decent way to monitor your re-equalization attempts.